Time, space, and energy phenomena can be observed at various scales using models to study systems that are too large or too small.

Engage

5 minutes

As students enter the room, they pick up their journals and begin responding to the prompt:

Name two types of bonding and describe at least one of them (without using your notes).

While students write, I circulate through the room in order to have a better idea of how well they understood the flipped notes for the section and as an accountability measure to check that the students are aware of the types of bonding discussed in the notes.

Once most students have finished writing, I ask for volunteers to share their thoughts with the class. One student volunteers and uses the word cell instead of atom. I told her that I understood what she meant, but asked her to review her work and think about her wording. She read through her work again, but did not catch the mistake. I then pointed to the atom model I was standing by and asked her what it represented. At that point, she realized that she had written cell instead of atom. She changed this in the first instance on her journal, but failed to correct it in the rest of the entry. This provided an opportunity to discuss the similarities and differences between atoms and cells. I believe the student became confused by the fact that we discuss both cells and atoms having a nucleus, though we have not yet discussed cells in this class.

After providing students with the opportunity to share their thoughts, I ask them to take out their flipped notes.

Student Journal

Explain

20 minutes

This is the flipped notes presentation about bonding that I created for my students. This concept can be difficult for students to understand, so the notes are rather minimal as I use a variety of modeling and discussion in class to help the students better understand the topic. The use of various models, both teacher and student created, helps to meet Science and Engineering Practice 2 - Developing and Using Models, specifically "Develop a model to describe unobservable mechanisms."

The Cross Cutting Concept Scale, Proportion, and Quantity specifically is addressing how “Time, space, and energy phenomena can be observed at various scales using models to study systems that are too large or too small, is also addressed through the creation of models.”

These activities also create a foundation for developing models to describe the atomic composition of molecules (NGSS - MS-PS1-1).

While reviewing the notes, I ask the students to add the terms cation and anion to their notes as well as adding that ionic bonds occur between metals and nonmetalswhile covalent bonds occur between two nonmetals. In order to help the students better understand covalent bonding, I ask them to identify familiar word parts. They recognize that the prefix "co" means together or with. (Some hints if they don't - coauthor, cocaptain, cofounder, coinventor, coworker.) I then ask them if valent sounds like anything we have been discussing and they are able to make the connection between valent and valence. I explain that covalent, then, is the sharing of valence electrons.

Before going too much further into the concept of bonding, I introduce Bohr models. I briefly show the students a few different variations of the models and explain that creating the models will better help them understand bonding.

I quickly review the energy levels with the students and explain that one level must be filled with electrons before another level can be started. I hand out the Bohr Model Practice guidelines and show the students how to use them. We complete the worksheet together. I also model the variation in which the number of electrons rather than individual dots are written on the separate energy levels.

Bohr Model Practice

Bonding Notes Review

Explore

After leading the class in whole group practice creating Bohr models, I tell the students that I was fortunate enough to find some electrons at the store. I then pull out a bag of M & Ms minis and turn them sideways so the Ms look like Es. I explain that each student will receive a few electrons. They need to count their electrons to determine which element they are creating a Bohr diagram for, and then create the diagram. After I have checked their work, they are free to eat their electrons and then begin working on the homework for the evening.

As I hand out the M&Ms, I try to make sure that students have between ten and thirty. When students finish their M&M model, I check it. The most common errors in this activity include not drawing enough or drawing too many electrons. I tell the students that this error can be avoided by counting their dots when they have finished drawing. Using the M&Ms is helpful to some of the students because they can simply place the M&Ms on their paper as the electrons. I still have them draw what they have created with the candies so they have something to refer to when working on their homework. This individual work time allows me to help the students as is seen in this Bohr diagram discussion video.

M&M model

Bohr Diagram Discussion

Wrap up

5 minutes

If there is enough time after all of the students have finished their M&M Bohr model, we go around the room and discuss how many valence electrons they have and whether or not they would be able to bond with any of their classmates.